Making the pilgrimage to a temple of the farm-to-table movement in January might seem foolhardy, especially when the place is in New York state, not Napa Valley. The air is frigid, the ground frozen, and any exposed crops have withered on the vine. What would we eat? Duo of Potato and Flight of Cabbage?

I knew that wouldn't be the case at Blue Hill at Stone Barns, which chef Dan Barber and family opened in 2004 as a way to show diners how their food is raised. Barber, who also operates Blue Hill in Greenwich Village, has deep roots in Northeast farming: Blue Hill Farm in Great Barrington, Mass., has been in his family for three generations. His restaurants were inspired by the farm, not the other way around, so if anyone could prove that the line from field to fork could be direct -- even in the dead of winter -- it would be Barber.

That's the main reason friends and I met for a Hudson Valley weekend, to check out Blue Hill's approach to cold-season cooking. But I had another goal as well: to see whether Tarrytown could keep us busy for a couple of days, or whether we'd be dreaming of the short train ride to Manhattan by the time our meal was over.

As is the case with seemingly everything else in the area, Blue Hill's home, the Stone Barns Center for Food and Agriculture in Pocantico Hills, is connected to the Rockefellers, who built a dairy farm in the 1930s because they wanted access to fresh milk. When Peggy Rockefeller died in 1996, her husband, David, and daughter decided to renovate the majestic barns and create the nonprofit center to honor her commitment to agricultural preservation. Today, Stone Barns is more than an educational center; it's a four-season working farm and the primary supplier of Blue Hill, its for-profit tenant.

On Friday we took the Metro-North line from Manhattan to Tarrytown, a 35-minute trip on the express train. We settled in at the Sheraton and hitched a four-mile ride to Blue Hill on the hotel's shuttle, passing Union Church and its stunning Chagall and Matisse windows (another result of Rockefeller philanthropy). The temperature was in the teens, so we hurried through the imposing, almost medieval stone complex and into the restaurant's bar, where a fire crackled and we got down to the serious business of ordering cocktails. The first hint of the creativity to come arrived in flights of liquors infused with such flavors as quince, oat/honey, fig/fennel and beet.

At our table, the server put to rest any lingering fears about winter food variety when she handed us what passes for Blue Hill's menu: a daily list of ingredients, labeled as coming from Stone Barns ("greenhouse," "pasture," "field" and "preserved") or not ("ocean," "river/lake," "Hudson Valley" and "beyond"). For the record, 67 items had been harvested from the farm outside, 35 had been grown within 175 miles, and 24 had come from ocean, river or simply "beyond." Not bad for the week before Groundhog Day.

There's no ordering at Blue Hill; you sign on for a tasting menu and wait to see what the kitchen delivers. And deliver it did. Our favorites were tiny, sweet, hot beet sliders; long marrow bones topped with paddlefish caviar; and a silky-textured hake with barely cooked mussels and a schmear of "greenhouse marmalade," salty and sharp. Instead of Barber's signature "vegetables on a fence," fresh produce stuck on a line of spikes, we received the winter version: a wood block with slits filled with chips of red potatoes, smoked kale and sage.

In hindsight, perhaps we experienced Blue Hill and Stone Barns in the wrong order: Rather than starting with a tour of the farm and then eating dinner, we did the reverse. On Saturday, we braved the cold for a toe-numbing, 90-minute "insider's tour" of Stone Barns led by Nena Johnson, public programs director. In her red barn jacket and jeans, Johnson provided an overview of the farm's history, then took us into the restaurant's huge, gleaming kitchen, where each trash can was labeled for one of two destinations: the compost or the pigs. Then she led us into the all-but-frozen fields. I say "all-but-frozen" because plastic-covered hoops sheltered one large section, which helped keep the spinach growing at 45 or 50 degrees.

The cold is an advantage to many vegetables, in fact. "The plant converts its starch to sugar in sort of a last-ditch attempt to not freeze," Johnson said. "You pull up a carrot in January or February, and it's the sweetest one you've ever had."

Some of the systems are higher-tech. For instance, the 22,000-square-foot greenhouse, developed with the help of four-season-farming guru Eliot Coleman, has a programmable system of roofs that open and close to regulate temperature. It is minimally heated through the use of propane and by capturing heat from a compost system. Inside the greenhouse, we saw the same varieties of microgreens that we had tasted the night before.

Out at the livestock barns, Johnson showed us the chicken coops on wheels, inspired by Polyface Farm's Joel Salatin, as well as the pigs and sheep. The ewes were being watched over by Stella, a Maremma sheepdog who seemed gregarious and sweet -- but only because no predator was threatening her flock, Johnson assured us. We wondered why the ewes had blue or red markings on their backsides. Johnson explained that the farmers had put large markers on harnesses attached to two rams and were tracking which one was mating with which ewe. The score made it obvious: The blue guy was on fire.

Seeing the farm thrive in midwinter, when the beehives are dormant and the ground crunchy with frost, made us vow to return in the summer -- or even earlier. A four-season farm and the restaurant that cooks from it demand to be experienced in each of the seasons. Besides, come May, there's a thrice-weekly farmers market, and for those of us who cook, such a thing presents yet another reason to visit. Surely we could find a nice rental nearby with a well-equipped kitchen?

As it happened, we had to content ourselves with a stay in the Sheraton and an afternoon of antiquing (read: huddling in one store after another for warmth) and lunching in Tarrytown. Frankly, after we sampled some of the pastries at another Blue Hill operation at Stone Barns, its little cafe, lunch in town didn't quite measure up. And without a car, we could not easily get to Kykuit, the Rockefeller estate, or any of the area's other mansions, let alone take a closer look at the windows at Union Church. So we waited for a cab to take us back to the hotel, then caught a shuttle to the train station and spent the remaining half of the weekend in Manhattan, only 30 miles from the farm but another world altogether.